1. Field of the Invention
The invention relates generally to the field of air dropped munitions, and particularly to incendiary projectiles for destroying hard or soft targets that contain biological or chemical agents or are flammable.
2. State of the Art
Various devices and methods for delivering incendiary and/or high explosive materials to a target for piercing the target are known in the art. For example, U.S. Pat. No. 4,318,343 to King describes a dual mode incendiary bomblet designed to penetrate building roofs and ignite fires within buildings. The bomblet includes a steel or aluminum penetration point 12, a tubular body 11, an aft closure 13, and a dual mode incendiary package 14 located within the tubular body 11. The incendiary package 14 contains a jetting incendiary 19 and a slow burning incendiary 20. The jetting incendiary 19 is made, for example, from a combination of plaster of paris and aluminum powder, and provides an extremely hot jetting flame. The slow burning incendiary 20 is made, for example, of a thickened hydrocarbon such as napalm, and provides a cooler but longer burning flame than the jetting incendiary. These incendiaries require an external oxygen source such as air in order to burn.
In operation, the bomblet is dropped from an aircraft. Upon striking the roof, a contact fuze in the bomblet is activated and in turn activates a delay train. After passing through the roof, the bomblet comes to rest on a horizontal surface in the building. Upon completion of the delay in the delay train, the delay train detonates an ejection cartridge 15 located in the bomblet forward of the incendiary package 14. When the ejection cartridge 15 is detonated, gaseous products generated by the cartridge 15 build gas pressure within the bomblet until the gas pressure blows off the aft closure 13 and ejects the incendiary package 14 out of the housing. Flame from the ejection cartridge 15 ignites a flammable case surrounding the incendiary package 14 at the same time the incendiary package 14 is blown out of the housing. During ejection of the incendiary package, the burning case surrounding the incendiary package 14 ignites incendiary igniters 23, 24 which ignite the jetting incendiary 19 component of the incendiary package 14. Passages 21, 22 are provided in the jetting incendiary 19 to focus jets of flame and hot gasses. The burning jetting incendiary 19 ignites the slow burning incendiary 20. Flame jets from the jetting incendiary 19 pierce objects that have generally non-flammable coverings, such as steel desks or book cases, and the slow burning incendiary 20 ensures that contents of pierced objects, such as paper documents are ignited.
U.S. Pat. No. 3,797,391 to Cammarata, et al. discloses an incendiary bomblet that includes several shaped charges oriented in different directions to perforate hard structures and propel incendiary particles through the perforations.
U.S. Pats. No. 5,561,261, 5,565,648 and 5,594,197 to Lindstadt et al. describe a tandem warhead having a shaped charge at the front and a secondary, explosive projectile at the rear that is capable of surviving detonation of the shaped charge. Detonation of the shaped charge creates a channel in a target, and the secondary projectile travels down the channel before exploding.
U.S. Pat. No. 5,157,221 to Ronn discloses a projectile that has a forward oriented, shaped charge explosive and an adaptive fuze in a nose of the projectile. In operation the adaptive fuze determines whether the projectile has hit a hard or a soft target. If the projectile hits a soft target and not a hard target, then the fuze detonates the explosive after a delay. If the projectile hits a hard target, the fuze detonates the explosive immediately.
U.S. Pat. No. 5,259,317 to Lips discloses a shaped charge explosive that has a waveguide element 2.1, 2.2 made of an incendiary material. Making the waveguide element 2.1, 2.2 out of an incendiary material enhances a pyrophoric effect of the explosive on a target. Incendiary material 3.1, 3.2 can also be provided on an inside surface of the shaped charge.
U.S. Pat. No. 4,932,326 to Ladriere discloses a piercing projectile that includes a hard, cylindrical body 6, an auxiliary projectile 3, and a propulsive charge 4. The auxiliary projectile 3 is positioned within the cylindrical body 6 and in front of the propulsive charge 4. When the projectile hits a target, a fuze 17 in the nose of the projectile ignites the propulsive charge 4, which drives the auxiliary projectile 3 through the hollow center of the cylindrical body 6 toward the target. Cavities 13 can also be provided on an inside surface of the cylindrical body 6 and filled with an incendiary material, so that passage of the auxiliary projectile 3 and hot gasses from the propulsive charge 4 through the cylindrical body 6 ignite the incendiary material.
U.S. Pat. No. 4,648,324 to McDermott discloses a penetrating projectile that includes a shell body with a penetrating rod 24 within the shell body. An incendiary material 48 is located in the nose of the shell body in front of the penetrating rod 24. An annular ring 26 supports a head of the penetrating rod 24 within the shell body and acts as a sabot. Gas producing charges are located in the shell body immediately behind the sabot, and a high explosive charge 50 is located behind the gas producing charges. Long-burning incendiary material is located behind the gas producing charges in the rear of the shell body. When the projectile hits a target, the incendiary material 48 in the nose of the projectile and the gas producing charges behind the annular ring ignite. The gases produced by the charges behind the annular ring propel the annular ring and the penetrating rod 24 toward the target.
U.S. Pat. No. 5,309,843 to Rentzsch et al. discloses a warhead with a tandem charge. In particular, a forward-oriented, shaped charge explosive is located at the front of the warhead, and a secondary, fragmentation projectile is located behind the shaped charge. On impact with a target, the shaped charge detonates and creates a hole in the target. Momentum carries the secondary projectile through the hole and into the target, where a delayed fuze detonates the secondary projectile for maximum effect.
However, none of the conventional techniques and designs provide an improved hard target incendiary (IHTI) projectile that is relatively inexpensive, robust, and capable of penetrating hardened or soft targets such as underground or surface structures and/or concrete bunkers and immolating contents of the targets such as chemical and/or biological warfare agents without spreading unacceptable amounts of undestroyed contents outside the structures.